Turbine radial diffuser



Jan. 23, 1968 K. JASSNIKER TURBINE RADIAL DIFFUSER 2 Sheets-Shet 1 Filed May 10, 1965 v /m/em0r.' Ku n Jossn i ker ATTORNEYS 2 Sheets-Sheet 2 Filed May 10, 1965 FIG. 2

lNVENTOR Kurr Jqssniker Eavw mw m 1 ATFIJORNEYS I United States Patent 3,365,120 TURBINE RADIAL DIFFUSER Kurt Jassniker, Winterthur, Switzerland, assignor to Sulzer Brothers Limited, Winterthur, Switzerland, a Swiss company Filed May 10, 1965, Ser. No. 454,585 Claims priority, application Switzerland, May 11, 1964, 6,087/64 4 Claims. (Cl. 230114) ABSTRACT OF THE DISCLOSURE There is disclosed a turbo-compressor having a radial diffuser at the outlet from the turbo-compressor, the diffuser being bounded in part by an axially movable wall. The side of this wall remote from the diffuser space is divided into two parts by an annular partition. These two parts constitute each a part of the boundary of a separate substantially closed space and means are provided to apply separate fluid pressures in these two spaces, so as to permit a substantial balancing of the total axial stresses operative on the movable wall.

The present invention relates to turbines and more particularly to apparatus for effecting adjustment of the cross-section of the radial diffuser of a turbo-compressor. The invention provides apparatus of this character in which one of the axially limiting walls of the diffuser is axially movable by means of an annular piston which surrounds the compressor inlet coaxially of the compressor, the piston operating on the movable diffuser wall via an annular linkage member which likewise coaxially surrounds the compressor inlet.

It is an object of the invention to provide simple and dependable means for adjusting the position of one wall of the diffuser in a turbo-compressor. In a typical use of a turbo-compressor such as the closed cycle of the working substance of a refrigeration plant, this adjustrnent must be effected against forces operating on the wall which may amount to several tens. Dependable and satisfactory adjustment of the diffuser cross-section by motion of one of its end walls against forces of this kind has hitherto presented substantial difficulties.

According to one feature of the invention, in order to minimize the load on the adjusting mechanism caused by these forces, the rear side of the adjustable wall (i.e., the side thereof away from the diffuser space) and certain portions of the housing are constructed to enclose together a hollow closed space, this space being filled with fluid under pressure so that the stresses operative axially of the machine on the movable wall will be nearly in equilibrium. In a preferred embodiment of the invention, the rear side of the adjustable wall is fitted with an axially-extending partition which divides the hollow space into at least two parts sealed off from each other, these two parts each being bounded in part by a separate portion of the rear surface of the movable diffuser wall. With suitable pressures applied in these hollow spaces, the total axial stresses operative on the movable wall nearly balance each other out.

Advantageously one of these hollow spaces is connected to the diffuser outlet whereas the other may be connected to a point downstream of the compressor-rotor or with the suction side of the compressor.

The invention will now be described in further detail in terms of two non-limitative examples by reference to the accompanying drawings in which:

FIG. 1 is an axial section through a single stage compressor according to the invention; and

Patented Jan. 23, 1968 FIG. 2 is an axial section similar to that of FIG. 1 but showing another form of single stage compressor according to the invention.

Referring to FIG. 1, the compressor-rotor 1 is driven from the shaft 2 by a motor not shown. The gas to be compressed passes axially through the suction inlet line 3 and thence to the compressor inlet space 4. It is then forced radially outward by means of the rotor blades 5. From the outward limit of the rotor the working substance passes into the diffuser 6, flowing between the diffuser walls 7 and 8 to the spiral 21. For adjustment of the flow cross-section of the diffuser 6, one of the diffuser walls 7 is built to be adjustable in position. By adjustment of the position of this wall, control is effected on the rate of flow of gas or other working substance through the compressor.

The inlet conduit 4 together with the compressor housing 9 encloses a space 10 in which an annular piston 11 is movably disposed. The two parts 10a and 10b of this space defined by the piston are connected to a'hydraulic system not shown, by means of which oil under pressure can be supplied to and withdrawn from the spaces 10a and 10b at will in order to effect axial motion of the piston 11.

Piston 11 is coupled to the movable diffuser 'wall 7 by means of a linkage which is likewise preferably coaxial with the compressor and which likewise preferably surrounds compressor inlet 4. In the example illustrated, this linkage comprises a cylindrical tube 12 which surrounds the inlet 4, together with a conical coupling element 13 which connects the tube 12 with the wall 7. The linkage comprising elements 12 and 13 together with the rear face 22 of the diffuser wall 7 and the compressor housing 9 enclose a hollow space which is divided into two parts 16 and 17 by means of a radial partition 14 in the housing and an axially extending cylindrical partition 15 formed on the rear side of the dividing wall 7. The spaces 16 and 17 are sealed off gas-tight from each other by means of a rubber ring packing 18 accommodated in a circular groove of the cylindrical partition 15, the packing being engaged with the radial partition 14.

A fluid under pressure is provided in each of the spaces 16 and 17. This fluid may be provided by the working substance to be compressed, withdrawn at a suitable point from the flow cycle thereof. Thus in the embodiment illustrated the space 17 is connected to the diffuser outlet via the circular slot 19 whereas the space 16 is connected with the inlet to the diffuser by openings 20 in the conical coupling member 13. By means of the connections 19 and 20, unlike pressures are maintained in the spaces 16 and 17 so that the space 16 is subjected to the pressure existing at the inlet to the diffuser whereas the space 17 experiences that existing at the outlet from the diffuser. In this way, the forces exerted by the fluid being compressed on the side of the wall 7 exposed to the diffuser space may be substantially balanced outwith the aid of the pressures in the spaces 16 and 17. The adjustment of position of the wall 7 is in this way much facilitated.

The embodiment of FIG. 2 is similar to that of FIG. 1 except that in the embodiment of FIG. 2 the space 16 is connected to the inlet line 3 of the turbo-compressor by means of a conduit 23 and not to the inlet to the diffuser 6, the openings 20 of FIG. 1 being absent in FIG. 2. The space 16 is therefore subjected to the inlet pressure of the turbo-compressor rather than to the pressure at the inlet to the diffuser immediately downstream of the rotor blades 5.

While the invention has been described herein in terms of a presently preferred embodiment thereof, theinvention is not limited thereto, but comprises all modifications on and departures therefrom falling within the spirit and scope of the appended claims.

I claim:

1. In a turbo-compressor comprising a rotor and a stator, the combination therewith of a diffuser having a fixed wall and a movable Wall, motor means coupled to said movable Wall, a cylindrical partition affixed to said movable wall on the side thereof remote from said fixed wall, stationary means defining with said partition two annular spaces each bounded in part by a separate portion of said side of said movable Wall, and means to apply pressures to said spaces.

2. The combination of claim 1 including means to conmeet one of said spaces with the outlet of said diffuser.

3. The combination of claim 2 including means to connect the other of said spaces with the outlet of said rotor.

4. The combination of claim 2 including means to ill connect the other of said spaces to the inlet to the turbocompressor.

References Cited UNITED STATES PATENTS 2,684,634 7/1954 Schneider 1()3-97 2,861,774 11/1958 Buchi 253-52 3,032,259 5/1962 Jassniker 2301 14 3,150,650 9/1964 Drcesen et al 2301 14 3,204,863 9/1965 Husammann 10397 FOREIGN PATENTS 234,751 5/ 1911 Germany. 133,892. 9/ 1929 Switzerland.

DONLEY J. STOCKING, Primary Examiner.

HENRY F. RADUAZO, Examiner. 

